USB: dummy-hcd: remove unsupported isochronous endpoints

The dummy-hcd driver doesn't support emulation of isochronous
transfers.  Therefore it doesn't need to export isochronous endpoint
descriptors; they can be commented out.

Also, the comments in the source code don't express clearly enough the
fact that isochronous isn't supported.  They need to be more explicit.

Finally, change the error status value we use (in theory) for
isochronous URBs.  checkpatch complains about ENOSYS; EINVAL is more
appropriate (it is documented to mean "ISO madness").

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 35 insertions, 18 deletions

diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index d177d63e16d7..671338827951 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -23,6 +23,8 @@
  *
  * Having this all in one kernel can help some stages of development,
  * bypassing some hardware (and driver) issues.  UML could help too.
+ *
+ * Note: The emulation does not include isochronous transfers!
  */
 
 #include <linux/module.h>
@@ -137,6 +139,9 @@ static const struct {
 		.caps = _caps, \
 	}
 
+/* we don't provide isochronous endpoints since we don't support them */
+#define TYPE_BULK_OR_INT	(USB_EP_CAPS_TYPE_BULK | USB_EP_CAPS_TYPE_INT)
+
 	/* everyone has ep0 */
 	EP_INFO(ep0name,
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
@@ -145,64 +150,72 @@ static const struct {
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep2out-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
+/*
 	EP_INFO("ep3in-iso",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep4out-iso",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)),
+*/
 	EP_INFO("ep5in-int",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep6in-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep7out-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
+/*
 	EP_INFO("ep8in-iso",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep9out-iso",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)),
+*/
 	EP_INFO("ep10in-int",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep11in-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep12out-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
+/*
 	EP_INFO("ep13in-iso",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep14out-iso",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)),
+*/
 	EP_INFO("ep15in-int",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)),
+
 	/* or like sa1100: two fixed function endpoints */
 	EP_INFO("ep1out-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep2in-bulk",
 		USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)),
+
 	/* and now some generic EPs so we have enough in multi config */
 	EP_INFO("ep3out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep4in",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep5out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep6out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep7in",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep8out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep9in",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep10out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep11out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep12in",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep13out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 	EP_INFO("ep14in",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_IN)),
 	EP_INFO("ep15out",
-		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)),
+		USB_EP_CAPS(TYPE_BULK_OR_INT, USB_EP_CAPS_DIR_OUT)),
 
 #undef EP_INFO
 };
@@ -1923,13 +1936,17 @@ restart:
 		limit = total;
 		switch (usb_pipetype(urb->pipe)) {
 		case PIPE_ISOCHRONOUS:
-			/* FIXME is it urb->interval since the last xfer?
-			 * use urb->iso_frame_desc[i].
-			 * complete whether or not ep has requests queued.
-			 * report random errors, to debug drivers.
+			/*
+			 * We don't support isochronous.  But if we did,
+			 * here are some of the issues we'd have to face:
+			 *
+			 * Is it urb->interval since the last xfer?
+			 * Use urb->iso_frame_desc[i].
+			 * Complete whether or not ep has requests queued.
+			 * Report random errors, to debug drivers.
 			 */
 			limit = max(limit, periodic_bytes(dum, ep));
-			status = -ENOSYS;
+			status = -EINVAL;	/* fail all xfers */
 			break;
 
 		case PIPE_INTERRUPT: